Well, you remember his horrible car accident that did and sometimes did not cause his back injury and also caused his face to be near scorching flames without leaving any noticeable burns? He told on himself while attempting to gain sympathy. Per his version of the accident, he was getting onto a freeway via on-ramp. He went up the on-ramp, merged onto the freeway, and changed lanes to the left lane. It was at this point that Vin Diesel came screaming up WAY TOO FAST DOOD and caused Phil to swerve and crash.
What this tells us is that Phil is one of those people who does not use the on-ramp to get up to proper speed like he is supposed to, moved over into the fast/passing lane, and was not going an appropriate speed. Then, when faced with the consequences of his poor driving decisions, he freaked out and crashed.
So yeah, shit driver IRL, and that's before we take into consideration that he doesn't wear the prescription glasses he's supposed to wear. I honestly hope Kat is the one driving at this point b/c he's likely a legitimate danger to other drivers.